(Anglais) To solve the problem of large time shifts between renewable energy supply and user demand, power-to-H2 is a well-known option. In this framework, previous studies have shown that the direct coupling of a photovoltaic array with an electrolyzer stack is a viable solution. However, these studies assumed perfectly known operating parameters to optimize the setup. Moreover, they focused on maximizing hydrogen and minimizing the energy loss, while the cost was not addressed. We have performed an optimization including uncertainty quantification (i.e. robust design) with the Levelized Cost Of Hydrogen (LCOH) as objective. This paper shows how the uncertainties could have a great impact on the conclusion of the optimization. It also provides which parameters are most affecting the variability of the output. The deterministic design optimization demonstrates that the system LCOH is best at locations with a high average yearly solar irradiance, where the system in Johannesburg produces hydrogen at 6.6 €/kg. The most robust system design is also established at Johannesburg. A standard deviation of 0.72 €/kg is achieved, where the discount rate uncertainty is the main contributor to the LCOH variation. Therefore, installing a PV-electrolyzer system in locations with a high average yearly solar irradiation is favourable for both the LCOH mean and standard deviation, and restricting the discount rate range has the highest impact on further reducing the LCOH variation. Future works will focus on adding batteries to the system.